Applications for smaller, more sophisticated components in the electronics industry have generated a corresponding demand for reliable, miniaturized connectors. For example, the advent of the electronic calculator, digital watch and personal computer has transported the requirements for devices from the realm of specialization to virtually one of commodity status.
Many types of connectors have been devised for interconnecting circuit boards to each other or computer chips. Exemplary of more recent developments are the connectors illustrated in U.S. Pat. No. 4,295,700 and ELECTRONICS, May 3, 1984, pages 135 to 136. Sado, U.S. Pat. No. 4,295,700, relates to a layered elastomeric based press contact interconnector employing a thin sheet of alternating dielectric and electrically conductive elastomeric layers sandwiched within an insulative housing in a manner where the peripheral portions along the edge lines perpendicular to the direction of anisotropical electroconductivity extend beyond the housing. Furthermore, the angle at which the peripheral portions project beyond the surface(s) of the housing is less than 80 degrees and more than 10 degrees relative thereto.
The ELECTRONICS article features a new Textronix, Inc. compression contact connector for interconnecting a 132-pin leadless chip carrier and a printed circuit board. The connector employs four elastomer devices, each disposed within a corresponding cavity in a square housing frame which is adapted to seat on a circuit board. The frame is secured to the circuit board by screws passing through an upper pressure plate, the frame and the board and then into an underlying stiffener frame. The chip carrier is lodged between the frame and pressure plate and is electrically connected to the board via elastomer devices upon compression of the pressure plate relative to the board upon tightening the screws.
The aforementioned connectors provide various desirable aspects for a connector such as wiping electrical contact, fixed interconnection using elastomeric connectors, reduced compressive load requirements, prevention of distortion of the interconnectors conductive pathways, capacity to rebound from the compressed to uncompressed state, minimization of contact resistance and an environmental seal against deleterious moisture and pollutants.
However, not all of these desirable features are found in any one particular connector. Moreover, the prior art connectors do not provide electrically conductive pathways which maximize efficiency, i.e. minimize path length and electrical resistance. Also, elastomeric connectors often fail to rebound completely upon release of compressive force therefore causing the connector to fail upon repeated compression and release.